Yapily's knowledge article about Berlin Group Payments
While PSD2 (Payment Services Directive 2) has mandated that banks must open their systems to third-parties, and provide interfaces for them to initiate payments and retrieve account information, in the UK it is the Open Banking Implementation Entity (OBIE) that defines how banks are to provide this information securely through APIs and data structures. In order to bring some synergy across the European banks, the Berlin Group which is a pan-European initiative has implemented a common API standard called NextGenPSD2. While these efforts have greatly improved how Open Banking can be consumed in member countries, there are some differences in how you communicate to these banks.
Note: When making a payment from an account held within the UK to an account held in Europe, the Payer object is not required since the payment is executed by an Institution that is a member of the Open Banking UK specification.